The volume of digital images, hereinafter also referred to as “images” for simplicity in the following discussion, that are available for consumption by users is ever increasing. As the volume of images increases, so too does the need for accurate and user friendly searching of the images. In order to find images with specific content, users often provide search terms or other criteria to a computing device to obtain meaningful results. For example, the computing device may perform an image search using the search term “boat,” and a group of images that have been identified as containing a boat may be returned. In typical digital images, a simple display of the returned images works well, e.g. via thumbnails, as the thumbnail typically captures an entirety of content included in the image, e.g., a particular object. However, basic thumbnail generation from panoramic images can be problematic due to the amount of content included even within a single image.
Panoramic images are typically viewed as 3D projections due to fields of view that are generally larger than that of a human eye. Because 3D projections generally require specialized viewers, such as Marzipano®, panoramic images are most often stored and viewed as two-dimensional (2D) projections, e.g. equirectangular projections and fish eye projections. Therefore, in order to return panoramic images in response to an image search, a conventional computing device typically generates a thumbnail of an entire 2D projection of the panoramic image. However, this may cause distortion to objects within the projection and result in an inability to discern individual objects within the projection. In another conventional technique, a computing device may create a thumbnail of a center portion of the 2D projection (where it is undistorted) to represent a panoramic image. Although the thumbnail of the centered portion is visually pleasing and comprehendible to a user, many of the objects within the image may reside outside of the thumbnail. Accordingly, if an image search involves an object that is outside of the thumbnail portion, the user will most likely determine that the image is irrelevant to the search even though the panoramic image contains the object. Thus, conventional techniques fail to generate useful thumbnails of panoramic images such that a user can easily see specific content within the panoramic images responsive to an image search.